In a gas turbine engine combustor, high temperature alloy heat shields are generally used to protect the combustor structure from the heat generated from the combustion process. As a result a heat shield mounting structure that can accommodate relative thermal deflections between components is generally provided to attach the heat shield to the combustor. Typical shield mounting structures include fasteners, for example studs, protruding from the heat shield and received in clearance holes defined in the combustor liner. Such clearance holes usually have a diameter sufficiently greater than that of the fastener received therein to accommodate the relative motion of the fastener caused by the thermal deflections.
It is known to retain each fuel injector within its respective opening defined in the combustor liner with the help of the heat shield. The large clearance holes generally used to retain the heat shield fasteners produce a certain inaccuracy in the location of the heat shield, thus in the location of critical features such as the fuel injector to combustor interface. While this inaccuracy may be acceptable in large engines, it can become problematic in smaller engines because of the reduced engine scale, the minimum available space, and the required manufacturing tolerances which do not scale with the engine size. In addition, smaller engines usually include an internal fuel manifold which increases the relative thermal deflections, thus increasing the necessary size of the clearance holes and as such the inaccuracy in the location of the heat shield.
Accordingly, improvements are desirable.